Removal of Acid Blue 92 by Using Amino-Functionalized Silica-Pillared Clay as a New Nano-Adsorbent: Equilibrium, Kinetic and Thermodynamic Parameters

چکیده مقاله

In this study, silica-pillared clay (SPC) and functionalized samples by chitosan (SPC/CTS) and different amounts of poly diallyl dimethylammonium chloride (SPC/PDDA-10, SPC/PDDA-20, and SPC/PDDA-30) have been synthesized and have been employed as some low-cost and eco-friendly adsorbents in the adsorptive removal of Acid Blue 92 (AB 92) from contaminated waters. The structural variation of functionalized and unfunctionalized samples confirmed by different techniques such as Scanning electron microscopy (SEM), Energy Dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and N₂ adsorption- desorption analysis. The SPC/PDDA-30 was selected for further studies due to its effective adsorption. The optimum values of adsorbent dosage, dye concentration, contact time and pH were found 0.02 g, 120 mg/L, 120 min and 5.0 respectively by applying response surface methodology (RSM). The adsorption equilibrium data were satisfactorily predicted by the Langmuir model and the adsorption process best fitted with a pseudo-second-order model. Adsorption thermodynamic analysis indicated the uptake of AB 92 on SPC/PDDA-30 was exothermic and spontaneous. The high adsorption capacity of the selected nanocomposite could maintain after five successive adsorption-desorption cycles by using 0.5 M NaOH. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim